Various types of pumps have been used for transfer and circulation of fluids for many years. In many cases the desirable pump design is a piston pump however one of the less desirable aspects of such piston pumps has been that such pumps are prone to output pulsation which requires either compensation or the willingness to live with such pulsation. One such attempt at reducing pulsation is shown in U.S. Pat. No. 5,145,339, the contents of which are incorporated by reference. While such a construction is a substantial advance over other prior art designs, some pulsation does remain.